CC attribution doesn't require you to necessarily have the credits immediately with the content, but it would result in one of the world's longest web pages as it would need to have the name of the poster and a link to every single comment they used as training data, and stack overflow has roughly 60 million questions and answers combined.
They don't need to republish the 60 million questions, they just have to credit the authors, which are surely way fewer (but IANAL)
appropriate credit — If supplied, you must provide the name of the creator and attribution parties, a copyright notice, a license notice, a disclaimer notice, and a link to the material. CC licenses prior to Version 4.0 also require you to provide the title of the material if supplied, and may have other slight differences.
Maybe that could be just a link to the user page, but otherwise I would see it as needing to link to each message or comment they used.
CC attribution doesn't require you to necessarily have the credits immediately with the content, but it would result in one of the world's longest web pages as it would need to have the name of the poster and a link to every single comment they used as training data, and stack overflow has roughly 60 million questions and answers combined.
They don't need to republish the 60 million questions, they just have to credit the authors, which are surely way fewer (but IANAL)
Maybe that could be just a link to the user page, but otherwise I would see it as needing to link to each message or comment they used.